Valve seat gauge



DCC- 20, 1932- F' ALBERTsoN ET Al. 1,891,364

VALVE SEAT GAUGE Filed Oct. 8. 1930 5 Sheets-Sheet l Dec. 2o,- 4193.2.

F. O. ALBERTSON ET AL .I la

VALVE SEAT GAUGE .3 Sheets-Sheet 2 Filed Oct. 8, 1930 l] Iliff/IWW zzz @WW a'. "www Q f/MM, AAJ/@y Deir. 20, 1932- F. o. ALBERTSQN ET AL 1,891,364

VALVE SEAT GAUGE Patented Dec. 20, 1932 UNI T E D STATE S PATENT OFFICE FRANS 0. ALBERTSON AND AXELV MADSEN, OF SIOUX CITY, IOWA, ASSIGNORS TO ALBERTSON & COMPANY, INC., OF SIOUX CITY, IOWA, .A'CORPORATION 0F IOWA.Y

VALVE SEAT GAUGE Application filed october s, 1930. seriaizN. 4.237.134.`

seat of an internal combustion engine before and after a valve seat rconstruction operation, to show the Aimprovement in the valve seat. Y

Another object is the provision of a dial gauge ofthe class described, which is capable of indicating the concentricity or lack of this quality of the valve seat, with respect to the valve guide, with a high degree of accuracy. Another object is the provision of a dial '35 gauge of the ciass described, which is adapted to bei used for checking valve seat reconstruction operations orreseating operations.

Another object is the provision of a. dial gauge of the class described, so arranged that -3 the dial may be held in fixed position instead of rotating withthe gauge arm in the eX- ploration of the valve seat surface, thereby permitting a closer reading than is possible with a moving dial.

Another object is the provision of an improved dial gauge for valve seats, which is sturdy, eiiicient, accurateV and capable of long service with a minimum amountof repairs or replacements of parts, and a gauge which may be manufactured at a low cost, within the means of a vast number of purchasers. I-

Other obj ects and advantages of the invention will be apparent from the following dein gs,. in which similar characters of reference indicate similar parts throughoutv the several views. Y

Referring to the drawings, of which there il, are three sheets;

Fig. 1 is an elevational view of oneof the preferred forms ofthe valveseat gauge, constructed according to the present invention;

Fig. 2 is asimilar view in a different r0- 'G tative position, with a part of the gauge body scription and from the accompanying draw-'- and indicator head shown in section, on a vertical plane on the line 2-2 of Fig. 1;

Fig. 3 is a'- pla'n view of the valve seat gauge; Y

Fig. 4 is ahorizontal, sectional view taken 5,3 on the plane of the line 4-4of Fig. 1, lookingin theV direction of the arrows;

Fig.v 5 isa sectional view taken on thepl'ane ofthe line 5-5 of Fig. 2; Y.

Fig. 6 vis a sectionalviewof the indicating y @3 ilnit, .takenfon the plane of the line 2 2 of Fig. 7 is a sectional view showing the means of supportlof .the indicator head on the pilotI stem7 taken on the plane ofthe line 7 -7 of 651 Fig. 2;

Fig. 8 isa view similar to'Fig. 15 of anotherof the preferred' forms of the invention; Y

Fig. 9 is a similar view in a diiferentrotative position, in partial ysection along the 'zo` plane of the line 9-9 of Fig. 8.

The present application 'relates specific-ally to theparticular type of valveseat gauge illustrated in Figs. 8 and v9.. Many of the features ofthe two types ofvvalvesea-tgauges 75 of Figs. 1 and 2 or Figs.4 8 and 9'are similar,

Aand therefore similar elements are designated by similar numerals, and the two embodiments-are described at the same time and differentiated by theirdiiferent characteristics. so The gauges: constructed according/'to the present-invention, areparticularly adapted to be used in: determiningthe condition of the valvev seatsv of internall combustion engines, or checking the efficiency of'valve seat recon- S5' struction orl reseating operations upon the type of valves having an axially located guide for slidablyy supporting a valve stem, commonly known as poppet valves. Many-of the features of the invention, however, are -of 90 general application,` and' may be utilized in connection with other surface gauging operations. Referring to Figs. 1 and 2, the presentl dial seat gauge 10 is illustrated in connection with 95 the block 11 of an internal combustion engine having a valve seat 12 and a valve guide 13. The gauge 10. is pereferably used in'iconnection with a pilot stem 14 of thetype adapted to be iixedly secured with its axis in alignment 100 with the aXis of the valve stem guide 13, and the same pilot stem is preferably employed which is used in the valve reseating or reconstruction operation. The pilot stem is thus in the same position which it assumed during the finishing'` of the valve seat, and the valve seat maybe checked to ascertain the condition of concentricity of the valve seat with respect to the pilot stem and to the axis of the valve stem guide 13.

The valve stem 14 preferably comprises a solid tool steel member having an upper tool receiving and guiding body 15 of substantially cylindrical shape and a lower cylindrical portion 16 of substantially cylindrical shape and adapted to fit in the cylindrical valve stem guide 13 quite closely.- For example, a complete set of pilots of this type preferably includes pilots of varying sizes, differing' in size by approximately one-thousandth of an inch, and therefore any guide may be fitted with a tolerance of one-thousandth of an inch or less, and the cylindrical portion 16 of the pilot corresponds quite closely to the size of the valve stem guide 13.

The ordinary valve seat guides are intended to be cylindrical and complementary to the cylindrical valve stem, but the ends of the guides usually become tapered from the wear and play of the valve stein. That part of the guide intermediate the ends and slightly spaced from the ends is generally most nearly truly cylindrical, and it is this medial cylindrical part' of the guide into which the cyllindrical portion of the pilot is intended to t.

Between the cylindrical portion 16 of the pilot 14 and the tool receiving body 15, the pilot stem 14 is preferably provided with a very gradually tapered or wedging portion 17 terminating in an annular shoulder 18, which definitely limits the degree of insertion of the pilot stem 14 into any guide 13. rlhe tapered portion 17 is of suiiiciently gradual L taper to be wedged into the pilot stem 13 by hand, the frusto-conical portion 17 of the pilot stem 14, automatically centering the pilot with respect to the guide 13 and the lower cylindrical portion 16 of the pilot also serving to center the pilot stem 14 within the limits of accuracy, which'are necessary for good work.

rlhe amount of taper at the frusto-conical portion 17 may vary for pilot stems of different sizes, but is preferably sufficient to permit the pilot to be iXedly secured in the guide 13 by the amount of force which can be applied with a pin passing through the transversev each foot of length of the pilot, and is preferably made about twenty-two thousandths of an inch per foot. The pilot stem is centered by the cylindrical portion of the stem, which fits quite closely the worn part of the guide intermediate the ends of the guide, and the pilot is secured in place by the wedging engagement of the tapered portion with the valve stem guide adjacent the ends and where the guide is apt to be slightly enlarged or rounded out.

The valve seat gauge preferably includes a substantially cylindrical body 20 having an axially extending bore 21 adapted to slidably and rotatably receive the cylindrical portion and the bore 21 preferably eX-V tends all of the way through the body in the gauges of the type shown in Figs. 1 and 2. At its upper end, the valve gauge body 20 is preferably provided with an annular flange 22, the outer cylindrical surface 23 of which may be lrnurled or milled to provide a convenient grip for the fingers in rotating the gauge body 20, and the head 24 of the body 2() is preferably provided with a flat .upper surface 25 and with an annular groove 26, thus forming another' annular flange 27 adapted to retain an indicating unit 28 on the gauge body.

The valve gauge body 2O preferably supports an adjustable collar 29 comprising an annular metal member having bore 30 for receiving the body 2O and having a pair of laterally projecting lugs 31, the annular member 29 being split at 32 between the lugs 31.

A threaded stud 33 is provided with a reduced end 34, which is secured in a complementary bore 35 in one of the lugs 31 by riveting, and the threaded end 36 of stud 33 eX- tends throu h an enlarged bore 37 in the other lug 31. i. lrnurled thumb nut 38 is threaded on the end 36 of stud 33 for engaging the adjacent lug 31 and clamping the lugs 31 together to liXedly secure thel collar 29 in any adjusted position on the body 20.

The collar 29 is also provided with a depending lug 39 which extends outward and downward from the collar 29 and is spaced sufficiently from the body 20 to make Yroom for the valve seat engaging member or arm 40, adjustably carried by lug 39. Lug 39 is preferably provided with a transverse bore 41 adapted to slidably receive the cylindrical portion 42 of a bolt having a threaded end 43 for receiving a thumb nut 44. The head 45 of bolt 42 may be cylindrical in form, and is preferably provided with a transverse bore 46 adapted to slidably receive the valve seat engaging arm 40 and the head 45 may be provided with a sleeve 47 with a similar transverse bore 48.

The thumb nut 44 is preferably provided with a. counter-bore located at its inner end and adapted to receive a coil spring 50 which is located in the annular space of counters bore 49 about the threaded portion of bolt 42.

The spring 50 is under compression and con- Y member V40 to be clamped between walls of bore 48 in sleeve 47, and the walls of bore 46 in head 45.

rlhe valve seat engaging member is thus resiliently clamped at all times, even when the nut 44 is out of engagement with the side of lug 39, butin such case, the valve seat engaging member may be readily released by axial'pressure on the nut 44. The resilient clampingV action of the spring may ybe augmented by threading the nut44 homeV against the side of lug 39-and ixedly clamping the arm 40 in any desired adjustedposition.

It should be noted that the arm 40 may be rotated on the bolt 42 or adjusted longitudinally of the bolt 42 as desired.

The valve seat engaging arm 40 comprisesV aV substantially cylindrical pin or rod prefer ably formed of tool steel .and provided at its lower end with a ball shaped formation 51 of hardened steel, which is adapted to provide a single point contact with that portion vof the valve seat 12 which the arm 40 engages.

Referring to Fig. 2, it will be noted that the valve seat engaging'arm 40 may be adjusted to a position transverse to the angle of the valve seat and ixedly secured on the body 2O bysecuringthe thumb nuts .38 and 44, after which the body 20 may be rotated by means Y of the annulus 22, and the valve lseat engaging member 40 will wipe around the valve seat 12to gauge the condition of thevalve seat surface. The valve seat engaging member 40 is peculiarlyadapted to be adjusted for valve seats of any angularity or valve seats of anyV diameter, and the various adjustments provided make the gauge adapt-able to the testing of Y'valve seats of all kinds.

The indicating unit 28, in the form of gauge shownin Figsfl and 2is preferably supported upon al separate indicator head 52 which mi f comprise a substantially cylindrical bot y having an eccentrically located bore 53 for receiving the head 24 of the gauge body 20. The head 52 is preferably provided with a transversely extending slot 54 permitting a convenient view of the upper surface 25- of the gauge body 2O and the'head 52 may be provided with a retaining member 55 comprising a sheet metal member secured to the head 52 with screw bolts 56 and having a downwardly extending flange 57 for preventing the'rocking of the head 52 on the end of body 20.

The iange 57 vprovides a bearing' surface for the annularflange 27 on the end of'body 20 atthe side of the slot 54, so thatfthe head 52 may rotate freely on the end of gauge bodyf20,b'ut'is guidedin its rotation bylflange 57 The headl v52V 'is' preferably retained on the end of body 2O by al setlscrew 58 which extends through the head 52 in the bore 53 and into the annular groove`26.' The annular groove 26 is of sufficient width with respect to the end of set screw 58, to permit the range of movement which may be desired for actuating the mechanism of indicating unit 28, but the set screw 58 retains the indi-eating unit and gaugebody 2O in assembled position at all times, although it permits sufficient axial movement of the head 52 to secure the indication desired.

The head 52 is preferably provided with a centrally located socket 59 at its upper end for receiving the casing 60 of the indicating unit 28. A bore 61 extends from the socket 59 to the bore 53 andvprovides space for an actuating plunger 62 which is operatively connected with the indicating mechanism in the indicating unit 28. The lower end of plunger 62 is preferably provided with a head 63 having a ball shaped formation 64 for engaging the fiat surface 25 of the gauge body 20. The indicator unit casing 60 may be secured in socket 59 by a plurality of set screws 65`or other convenientfastening means.

In the type of gauge shown in Figs. 1 and 2, the head 52 is preferably iixedly supported on the upper end of a pilot 14 during the gauging operation, and for this purpose the head 52 is provided with a bore 66 axially located with respect to bore 13 and adapted to closely fit the upper end of pilot 14. rlhe head 52 is also preferably provided with a frictional securing device, such as a spring pressed ball 67 which is located in a transverse bore 68 and adapted to engage the upper end 15 vof pilot 14.

The bore 68 is preferably threaded and a coil spring 69 is compressed between the ball 67 and an adjustable threaded plug 70. rlhe inner eud of bore 68 is tapered as at 71 and provided with an opening 72 of reduced size whichv is adapted to permit the ball 67 to project from the bore 68, but the inwardly projecting flange 73 retains the ball 67 in the bore'68. The head 52 maybe pressed on the upper end of pilot 14 by forcing the end 15 into bore 66, the beveledL end 74 of the pilot camming back the ball 67 which frictionally engages the body 15 of the pilot and tends to retain the head 52 in fixed position with respectto the pilot 14. In the gauging operation, however, the body 52 is also preferably held with the fingers of thev operator, thereby' retaining the indicating unit 28 in fixed position while the gauge vbody 2O is rotated by mea-ns of the fingers applied to annular flange 22.

Y TheV indicating' unit 28'preferably comportion 7 5 of casing 60 is provided with an annular boss 76 formed with a bore 77 for slidably receiving plunger 62, and a transverse frame member 78 secured by screw bolts 79 to the inner annular surface 80 of casing' 60 is provided with an aligned bore 81 for slidably supporting plunger 62.

A sheet metal guide member 82 is likewise secured to the annular surface by screws 83 and is provided with a downwardly extending slot 84 between the two legs 85 for guiding a pin 86 carried by plunger 62.

The lower portion 75 of the casing also houses a wire spring 87 having one end 88 soldered to the casing 60 and the other end 89 hooked over pin 86 and tensioned to urge the pin 86 and plunger 62 downward.

The casing 60 also supports, by means of screw bolts 90, another transverse metal frame member 91 having a centrally located .bore 92 for rotatably supporting the upper end of a spindle 93. The lower end of the spindle 93 is journaled in a bore 94 in casing 60. rhe spindle 93 is preferably provided with an enlarged shaft 95 formed with a worm groove 96 and with a pinion 97. The end of pin 86 extends into worm groove 96 and is adapted to rotate the pinion 93 when plunger 62 is moved axially. The transverse frame member 91 also supports a sheet metal bearing bracket 98, fiXedly secured to its lower side by screw bolts 99 and rovided with a bore 100 for rotatably receiving one end of a shaft 101, the other end being journaled in the bore 102 in frame member 91. y

rlhe shaft 101 supports a gear 103 which meshes with pinion 97 and a spiral spring 104 is wound about the hub of shaft 101 below gear 103, having one end attached to the shaft and having its outer end attached to bracket 98. Spiral spring 104 constantly uroes spindle 93 in a counter-clockwise direction and maintains the upper side of groove 96 in engagement with the pin 89 at all times. The springs 104 and 87 constantly take up any lest motion between the motion multi plying mechanism, which connects the plunger 62 and pinion 93, thereby causing the pointer 105 which is carried by pinion 93, to closely follow the movements of the plunger 62 without any back lash.

The casing 60 may be provided with an auxiliary Youter casing member 106 of substantially cylindricalform, adapted to receive the casing 60 and having an annular, inwardly extending flange 107 forV engaging the bottom of casing 60. `The outer case 106 extends above casing 60 and is adapted to enclose and support the dial 107 and transparent cover 108. For this purpose, one or more annular spring washers 109 may be interposed between dial 107 and upper end of casing 60 and the dial 107 may be iXedly secured in outer casing 106 by a split ring 110.

The glass cover or crystal 108 may be secured on the end o f outer casing 106 by -a bezel ring 111 having an inwardly extending annular flange 112 for engaging thecrystal and having a cylindrical body adapted to frictionally engage the outer wall of outer casing 106.

The dial 107 may comprise a cardboard or Celluloid plate having a centrally located bore 113 for passing the spindle 93 and having a circular scale with appropriate numerical indicia at regularly spaced scale divisions. If desired, however, only a few scale divisions may be provided along an arcuate line, since the present gauge is intended to measure only a small amountof divergence of the valve surface from the perfect condition.

Referring to Figs. 8 and 9, this modification is more simple than that described in det-ail with respect to Figs. 1 to 7 but this gauge is preferably provided with an indicating unit, pilot stem, gauge body and gauge arm, identical in construction with that previously described.

The gauge of Figs. 8 and 9 differs from that of Figs. 1 and 2, in that the head 52 in views 8 and 9, is lixedly supported upon the gauge head( 20 and the plunger 62 engages the upper end of the pilot stem 14 in igs. 8 and 9, instead of the upper end of gauge body 20 as in Figs. 1 and 2. y

Consequently, when the gauge body 20 is rotated in Figs. 8 and 9, to cause the arm 40 to wipe across the valve seat surface, the dial gauge or indicating unit 28 also rotates with the body 20 and it is more difficult for the eye ofthe operator to watch the pointer 105and dial 107, to observe any movement of the pointer. That is, it isV more diiiicult to read an instrument, the scale and pointer of which are rotating. f

The operation of the gauge shown in Figs. 1 and 2 is as follows. The reseating operation or valve seat reconstruction, is preferably accomplished with the same pilot stem 14 which is intended to be used with the valve seat gauge. If desired, the divergence of the valve seat from the desired condition may be Lil checked at the beginning of the reseating operation, to show the customer the poor condition of the valve seat by means of the gauge. After the seat has been reinished, the finishing tools are removed from pilot 14 and the gauge assembled, as shown in Figs. 1 or 8. The valve seat engaging arm 40 is preferably adjusted substantially as shown in Fig. 2, with respect to the valve seat, the ball 51 engaging the valve seat 12, and the nuts 38 and 44 being tightened.

The indicating unit 28 may then be held still by grasping the head 52 with the lingers and the gauge body 20 may be rotated by the ngersof the other hand applied to the annular grip 22. During this rotation, the arm 40 willwipe across the valve seat surface 12, but the arm 40 will be rotated in a circle about the axis of the pilot 14. The ball 51 will slide over the valve seat surface 12 and any divergence from true concentricity will permit the ball 5l to drop or rise slightly, which will cause a slight axial movement of the valve gauge body 20.

The same effect would be produced by any vdepression in the valve seat surface 12 and in the embodiment of Figs. l and 2 any downward movement of the body permits the plunger 62 to move downward, causing the pointer 105-to execute a larger movement relative to the dial 107 en account of the motion multiplying mechanism of the indii cating unit 28. In such case, the indicating` unit 28 and head 52 are supported in fixed position on the upper end oi" pilot stein 14, and the collar 29 must, of course, be adjusted so that the plunger 62 is not at the lower limit ofits movement.

Il the valve seat has been properly linished,

`the gauge will show but a very'slight moyement of the pointer 107, during the rotation of the gauge body 20, but it there are any irregularities in the valve seat 12, they may 4irregularity of the valve seat surface 12 the pointer 105 on the dial 107.

It will thus be observed that we have invented an improved valve seatgauge which is adapted to be adjusted for valve seats of any irregularity or diameter, and which is adapted to be used to check the valve seats before and after any reseating and reconstructing operations, to show the improved condition of the valve seat or the desirability of refinishing the set.

The improved type of gauge shown in Figs. 1 and 2 may be read more accurately than that shown iii Figs. V8 and 9, for the reason that the dial may be held still during the checking operation, and the present valve seat gauge is capable of a high degree of accuracy. The device shown in Figs. 8 and 9, however, has the advantage of greater simplicity of manufacture, and consequently that of greater economy.

`While we have illustrated a preferred emlarities on a valve seat to indicate .the eleva-" bodiment of our invention, many modifications may bemade without departing from the spirit of the invention, and we dov not wish to be limited to the precise details of construction set forth, but desire to availi` ourselves of all changes within the scope of the appended claims.

Having thus described our invention, what we claim is new and desire to secure by Letters Patent oit' the United States, is: 7 5

1. In a valve seat gauge, the combination of a pilot stem havino' a tapered portion adapted to be wedged into one end of a valve stein guide and having a cylindrical portion substantially complementary to the medialO cylindrical part of said guide, with a gauge havin@` a bod movabl .mounted on said ilot t. stem, indicating mechanism carried by-said gaugebody and including a plunger engaging said pilot stem, a gauge arm adapted toP S5 engage a valve seat and operative mechanism lincluding said plunger and gauge body connecting said indicating mechanism and said gauge `arm whereby said indicating mechanism is adapted to indicate the concentricity? of said seat with respect to said guide.

2. ln a valve seat gauge, they combination of a. pilot stem havingV a tapered portion adapted to be lwedged into one end of a valve stem guide and having a cylindrical portiont substantially complementary to the medial cylindrical part of said guide with a gauge having a body rotatably and reciprocably mounted on said pilot stem, indicating mech.- anism carried by said gauge body and hav: ing a part engaging said pilot stem, a gauge arm and means whereby said arm is carried by said body so as .to be reciprocated `with said body when said arm rotates over irregui135 tion of said 'seat at aV predetermined radius from the axis of said guide.

3. In a valve seat gauge, the combination of a pilot stem having a tapered portion adapted to be wedged into one end oi a valve' stein guide and having a cylindrical lportion substantially complementary to the medial cylindrical part ot' said guide, with a gauge having a body rotatably'and reciprocably mounted on said pilot stem, indicating mechanism carried by said gauge body and having a plunger adapted to engage the end of said pilot stem, an adjustable valve seat engaging member and means whereby said cylindricalpartof said guide,`a gauge having a body rotatably and reciprocably mounted on said pilot stem, indicating mechanism carried by Said gauge'body and having a plunger adapted to engage the end of said pilot stern, an adjustable collar carried by said gauge body, a rotatable stud carried by said collar, and a valve seat engaging arm slidably adjustable in said stud and rotatably adjustable with said stud.

5. A valve seat gauge comprising a cylindrical body formed with an axial bore for receiving a pilot stem, and carrying a head and having a socket for receiving an indicating unit, a dial indicator carried in said socket and having a plunger for engaging a ilot stem received in the bore of said body,

' an adjustable collar carried by said cylindrical body, a valve seat engaging arm and means for .slidably and pivotally supporting said arm on said collar.

6. A valve seat gauge comprising a cylindrical body formed with an axial bore for receiving a pilot stem, and carrying a head having a socket for receiving an indicating unit, a dial indicator carried in said socket and having a plunger for engaging a pilot stem rel ceived in the bore of said body,'an adjustable collar carried by said cylindrical body, a depending arm carried by said collar and having a transverse bore, a stud in said bore, a rod having a rounded end, slidably mounted in a bore in said stud and means for Vclamping said rod against said depending arm.

7. In a valve seat gauge, the combination of a pilot stem adapted to be lixedly secured in a valve guide, with a gauge body slidably and rotatably mounted on said pilot stem, an

indicating unit iixedly secured to said gauge body and having a plunger for slidably engaging the end of said pilot stem, an adjustable arm carried by said gauge body for engaging a valve seat, and means for movably mounting said arm on 'said gauge body for movement in lthe direction ot the length ot said arm whereby the eiective length of said arm may be adjusted for valve seats of dit ferent diameter.

8. In a valve seat gauge, the combination of a pilot stem adapted to be ixedly secured in a valve stem guide, said pilot stem having anupper cylindrical portion, a gauge body rotatably and reciprocably mounted on the cylindrical portion of said pilot stem, a collar carried by said body, a stud rotatably carried by said collar, anarmslidably adjustable in said stud, threaded means for moving said stud axially in said collarto clamp said arm, whereby said arm may beadjus't-ed normal to valve seats of different size and angularity,V

and means for indicating the axial movement of said gauge body on said pilot stem when said body is rotated to wipe said arm over the surface of a valve seat.

9. In a valve seat gauge, a gauge body comprising'a metal member formed with a bore 'for receiving a part of a pilot stem, said body bore for receiving a part of a pilot stem, said body having an enlarged integral head at its upper end, and said head having a socket for receiving an indicating unit, an indicating unit located in said socket and having a dependingV plunger located in said bore to engage said pilot stem, means carried by said body for engaging a valve seat whereby the variations in elevation oi said valve seat are transmitted to the mechanism of Vsaid indicating unit by said plunger, said head having anl inwardly extending slot located at one sidey below said indicating unit and communicating with said bore at said plunger to give access to said plunger and the end of said pilot.

1l. In a valve seat gauge, the combination ot a pilot member adapted to be ixedly secured in a valve stem guide, with a body member rotatably ,and slidably mounted on said pilot member, an indicating unit carried by one of said members and having a feeler projecting into engagementwith the other of said members, an adjustable collar carried by said body member and having a depending lug, provided with an aperture, a transverse stud rotatably mounted in said aperture, 'and a valve seat engaging arm carried by said stud and supported by said collar for angular adjustment, said arm comprising a hardened metal member provided with a hardened ball shaped formation at its seat engaging end for slidably engaging valve seats of different angularity.

In witness whereof, we hereunto subscribe. our names this 26 day of September,v1930. FRANS O. ALBERTSON. AXEL MADSEN. 

